I would guess that Tron's price tag includes all the other work required with relocating the canal, expanding the pond, building the retaining wall in front of the park for the berm/railroad tracks, rebuilding the railroad tracks, etc, etc, etc. There is a lot of prep work going into making this happen. Of course it will still run over budget and they'll have to cut a bunch of the bells and whistles anyway (like the upgrade to the raceway they had planned originally).